Topic:What is a GIS?

Aspatial Data

Spatial Data

Spatial Data:

Data with a “spatial component” describing where something is located in on the earth.

Formal Definition of GIS:

“A computer-based system to aid in the collection, maintenance, storage, analysis, output and distribution of spatial data and information (Bolstad, 2008)”

What is a GIS?

Elements of GIS

• Collection: Internet, web services, GPS…• Maintenance: Quality control, metadata…• Storage: Files, folders, databases…• Analysis: Too many to list!• Output: Maps, tables, reports, pubs…• Distribution: Websites, web services…

Which of these are a GIS?

• MS-Word• Excel• ArcGIS• Handheld GPS• GoogleEarth• MapQuest• Facebook• Twitter• Your cell phone

• Your computer• You!

A world of physical entities that occupy space: (plants, trees, rivers, streets, etc.)

– What: What are the physical features of interest and what are their properties and attributes?

– Where: Where are these physical features located, both in terms of their absolute locations (i.e., their coordinates) and their locations relative to other physical entities (their topology)?

– When: When are certain conditions true and how do things change over time

Modeling the real world

eographic: Geography is the scientific study of the locational and spatial variation in both physical and biological phenomena on Earth. (the “where”)

nformation: A collection of facts or data. (the “what”)

ystem: A group of interrelated parts working together (hardware, software, data, people…).

What is a GIS?

Get Answers to Questions

• What exists at a certain location?• Where are certain conditions satisfied?• What has changed in a place over time?• What spatial patterns exist?• How close are things to one another?• What if this condition occurred at this

place?

Questions from Managers

• When and where should we:– Spray for weeds?– Build roads?– Patrol for poachers?– Protect habitat?– Reintroduce species?– Harvest?– Monitor?– Allow off-roading?

With a GIS and spatial data you can ask spatially related questions:

1. The spatial distribution of object(s) or theme(s)Where is x? How is x distributed?

2. The relationship between the spatial distribution of objects or themes

Where is x in relationship to y?

3. The association of objects or themes in an area. Is there a correlation between the distribution of X and the distribution of Y?

Could X be causing Y?

What can I do with a GIS?

GIS Is About:

• Acquiring Spatial Data – representing things on the earth

• Evaluating – making sure data fits use• Analysis – turning data into information• Cartography – the creation of maps• Dissemination – distributing maps, data,

and results• Documenting – ensures future use

GIS Resources

• There are many resources:– The web, classes, books,

organizations, individuals• See Jim’s professional

website for more:– (add tinyurl)– You’ll want to know everything

on the quick reference

Geospatial Sciences

GIS

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The Bigger Picture

Geospatial Sciences: The science and technology of gathering, analyzing, interpreting, distributing, and using geographic information.

Basic concepts, skills, knowledge

General GIS:Data acquisition, management, analysis, and representation

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GIS is almost everywhere

• A GIS is not just a computer program for making maps.

• It is, first and foremost, a powerful analytical tool with a spatial “awareness” that allows you to analyze spatial data and answer complex spatial questions.

Key Points

Where are we?

GIS can broaden your view!